蒸馏分馏环己烯的制备.ppt

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1、SimpleDistillationandFractionalDistillation1.Purpose1.1StudytheprincipleandmethodsofSimpleDistillationandFractionalDistillationusedforpurifingorganicliquids.1.2Graspthetechniquesofsimpledistillationandfractionaldistillation.2.Principle2.1SimpledistillationWhenthevaporpressu

2、reoftheliquidbeingheatedequalstheatmosphericpresureonthesurfaceoftheliquid,itboils.Thetemperatureatthatmoment,iscalledboilingpoint.Simpledistillationisaprocessthatconsistsofboilingaliquidandcondensingthevaportotheliquidstate.Everypureorganiccompoundhasafixedboilingpointatac

3、ertainpressure.Wheneverpossible,simpledistillationisalwaysusedtoseparateliquidMixtureswhichhaveboilingpointsmorethanabout30℃apart.Butsometimesanorganiccompoundtogetherwithothercomponentscanformabinaryorternaryazeotropemixture(二元或三元共沸物）,whichalsohasadefinitebolingpoint.Soiti

4、sdifficulttosaywhetheraliquidisamorepureorganiccompound,basedonitsdefiniteboilingpoint.Theboilingrangeofapurecompoundisabout0.5-1℃.Butthatofmixtureisverylarger,usuallyyoucandeterminetheboilingpointofaliquidcompoundbydistillation.2.1FractionaldistillationFractionaldistillati

5、onismoreeffectivethansimpledistillationisalsoacommonlyusedtechniqueoftheseparationandpurificationofliquidorganicCompoundswithasmallerboilingpointdifference.Fractionaldistillationisadistillationoperationwithafractionatingcolumnwhichisequivalenttoseveralsuccessivesimpledistil

6、lations.Asthevaporfromthedistillationflaskrisesupthroughthefracionatingcolumn,itcondensesonthecolumnpackingandrevaporizescontinuously.Everyrevaporizationofthecondensateisjustaseparatedistillatin.Infact,vaporAndcondensatearepassinginoppositedirecionsthroughthecolumn.MoreVola

7、tilecomponentascendsthroughthecolumn,whilelessvolatilecomponentsdescend.Ifrepeated,thatmeanstheprocessgoesthroughmanyvaporization-condensationcyclesandhastheeffectofmanydistillations.2.Procedure2.1SimpledistillationFigure1TypicalApparatusforsimpledistillation图1普通蒸馏装置通水NOTES

8、Accordingtothe“bottom-to-up”and“left-to-right”principle.Makesurealltaperjointsarec